Compositions comprising sulfamide for increasing flame resistance of polymers

ABSTRACT

A composition for increasing flame resistance of a step-reaction polymer comprising sulfamide and certain organic acids or their metal salts, a method of using the composition to treat the polymer and the resulting treated polymer.

Unite States Patent 1191 1111 3,888,819 Evans et a1. June 10, 1975 COMPOSITIONS COMPRISING 2,381,487 8/1945 Cook et a]. 106/15 SULFAMIDE FOR INCREASING FLAME 2,912,394 11/1959 Stilbert et al. 117/138 3,409,463 11/1968 Le Blane et al. 106/15 RESISTANCE OF POLYMERS 3,785,858 1/1974 Chapin 117/138 [75] Inventors: Francis E. Evans, Hamburg, N.Y.; Kenneth B. Gilleo, St. Paul, Minn.

[73] Assignee: Allied Chemical Corporation, New

York, N.Y.

[22] Filed: Apr. 29, 1974 [21] ,Appl. No.: 465,224

[52] 11.5. C1. 260/453 N; 25218.1; 260/45 85 B; 1160/4585 V; 260/45.85 H; 260/4585 T; 1260/4585 S; 260/4585 P; 260/459 R; 1260/4575 R; 260/4575 K; 260/4575 C; 260/4575 W [51] Int. Cl C08g 17/56 [58] Field of Search..... 260/4585, 25 A], 45.9, 260/458; 106/15; 117/136; 252/81 [56] References Cited [UNITED STATES PATENTS 2,142,116 [/1939 Cupery 117/138 OTHER PUBLICATIONS Chemistry and Uses of Fire Retardants Lyons; 1970; pp. 413 and 414.

Primary ExaminerV. P. Hoke Attorney, Agent, or Firm-Michael L. Dunn; Anthony J. Stewart [57] ABSTRACT A composition for increasing flame resistance of a step-reaction polymer comprising sulfamide and certain organic acids or their metal salts, a method of using the composition to treat the polymer and the resulting treated polymer.

10 Claims, No Drawings 1 .1 COMPOSITIONS COMPRISING S'ULFAMIDE FOR INCREASHNG FLAME RESISTANCE OF I POLYMERS This invention relates to step-reaction polymers such as nylon which exhibit improved flame resistance. More specifically, the invention relates to nylon, polyester and polyurethane polymers treated with compositions which impart improved flame resistancethereto and to the process of so treating the polymers.

In the prior art numerous compounds'have been used as additives to step-reaction polymers to reduce flammability cf the polymers. For example inorganic and organic tin, phosphorous and halogen containing compounds have beenused to reduce flammability of nylon. These compounds have not, however, been entirely successful due to inefficiency or polymer degradation. i

In addition to the tin, phosphorous and halogen containing compounds, certain compounds containing nitrogen and sulfur have been employed to improve flame resistance. While some of these'nitrogen' and sulfur containing compounds are an improvement over the other prior art compounds, they still do not create as much flame resistance as is desired or necessary.

BRIEF DESCRIPTION OF TI-IE INVENTION The additive composition, with which the stepreaction polymers are treated, comprises:

a. sulfamide', and

crease in flame resistance, generally do not improve flame resistance to a desirable level. The step-reaction polymer is generally a polymer formed by the step-wise intermolecular condensation of reactive groups. These polymers have also been known as condensation polymers and includepolyesters, polyanhydrides, polyacetals, polyamides and polyurethanes. For a discussion of step-reaction'polymers, see Text Book of Polymer Science Second Edition, Fred W. Billmeyer Jr., John Wiley and Sons, Inc. 1971. The most preferred step-reaction polymers which are treated in accordance with this invention are nylon, polyurethane and polyesters.

The step-reaction polymer,- e.g. nylon, may be treated by wetting the surface of the polymer with a solution or emulsion containing the above composition.

The preferred compounds for use in conjunction with the sulfamide preferably comprise from about 40 to about 85 weight percent of the compositions and generally contain fewer then 10 carbon atoms although compounds containing more than ten carbon atoms may be used provided that the ratio of hydroxy groups plus mercapto groups to the number of carbon atoms is at least 1 to 5 and the ratio of carboxy groups to the number of carbon atoms is at least 1 to 5.

The polyhydroxy-polycarboxy acids are organic acids having a plurality of hydroxyl and carboxyl groups. Examples of suitable polyhydroxy-polycarboxy acids are 2,5 dihydroxy p-benzene diacetic acid; dihydroxy maleic acid; dihydroxy malonic acid; dihydroxy tartaric acid; mucic acid; gibberellic acid; alginic acid and dihydroxy adipic acid.

The mercapto polycarboxylic acids are organic acids having a plurality of carboxyl groups and at least one mercapto (SH) group. Examples of suitable merb. a compound selected from the group consisting polyhydroxy-polycarboxy acids and their metal and ammonium salts, mercapto polycarboxy acids and their metal and ammonium salts, polyhydroxy ben- DETAILED DESCRIPTION OF THE INVENTION In accordance with this invention a step-reaction polymer, such as nylon, polyester or polyurethane is treated with at least I and preferably about 2 weight percent of a composition comprising sulfamide and a compound selected from the group consisting of polyhydroxy-polycarboxy acids and their metal and ammonium salts, mercapto polycarboxylic acids and their metal and ammonium salts, polyhydroxy benzoic acids and their metal and ammonium salts, the lithium and sodium salts of monohydroxy polycarboxy acids, and the metal and ammonium salts of trithiocyanuric acid. Generally less than about 15 weight percent and preferably less than about 8 weight percent of the composition is used since generally the greater percentages do not materially increase flame resistance and can sometimes cause undesirable effects such as crocking, i.e. flaking on the surface of the polymerQPercentages lower than I weight percent, while providing some incapto polycarboxylic acids are thiomalic acid; 4- mercapto cyclohexane 1,2 dicarboxylic acid; mercapto adipic acid and mercapto phthalic acid.

The polydroxy benzoic acids are organic acids having a plurality of hydroxy groups and at least one carboxy group attached to a benzene ring. Examples of suitable polyhydroxy benzoic acids are gallic acid; 2,4,6 trihydroxy benzoic acid; trimethoxy benzoic acids; syringic acid; dihydroxy benzoic acids; hydroxy dimethoxy benzoic acids; hydroxy methoxy benzoic acids and dimethoxy benzoic acids.

The monohydroxypolycarboxy acids are organic acids containing one hydroxy group and a plurality of carboxyl groups. Examples of suitable monohydroxy polycarboxy acids are hydroxy malonic acid; citric acid; malic acid; hydroxy adipic acid; hydroxy phthalic acidand hydroxy cyclohexane 1,2 dicarboxylic acid.

The preferred metals used in forming metal salts of the polyhydroxy polycarboxy acids, polyhydroxy benzoic acids and trithiocyanuric acid are Group I, II, III, IV, V, VI, VII and VIII metals of the second, third, fourth and fifth periods of the Modern Periodic Table of Elements. The most preferred metals are Li, Na, K, Mg, Ca, Cu, Zn, Al and Sn. Of the most preferred metals, Li, Ca and Mg have been found to provide the best results although in certain cases alkali metals are generally more than satisfactory.

In treating the step-reaction polymer in accordance with the process of this invention, from about 1 to about 15 weight percent of the treating composition, as previously described, is applied to the step-reaction polymer. In practicing the invention, the composition is dissolved in solvent, usually water, to make a solution of about 0.5 to about 12 weight percent, more preferably from about 2 to about 8 weight percent and most preferably from about 4 to about 6 weight percent. The step-reaction polymer, usually in the form of fabric or pill is finished burning, the better the flame resistant properties of the carpet.

EXAMPLES carpet, is then soaked by the solution which may con- The following Table I shows the highest temperature tam other additives commonly used in finishing baths applied tp the carpet before the carpet fails to extinto ImPIOVE propertles Such as Pe e o Water guish within 90 seconds after the pill is finished burnbo y- The fabno of carpet 15 Squeezed Wlth y ing, the additive composition used, and the percentages Sultablo aPPaTatUS, Such P rollers, to remove of additive on the carpet. In each case in Table I it will ss s u lon h qu g ppa a such as the be noted that when sulfamide is used in combination adjusted to g from about to about 300 with a compound selected from the group consisting of wofgbt Percent, Preferably from about to about 200 polyhydroxy-polycarboxy acids and their metal and Weight D and most Preferably from about to ammonium salts, mercapto polycarboxy acids and their about 150 f b p i o o The fabrlc or metal and ammonium salts, polyhydroxy benzoic acids Carpet matorla] 15 drled m a dryer or oven 15 and their metal and ammonium salts, the lithium and at p p to out 1 50C. but p e y less sodium salts of monohydroxy polycarboxy acid and the {ban abbu? 125 0 Sblubbn may be abphed to the metal and ammonium salts of trithiocyanuric acid, the steb'rbabtlbb bblymbr m nbmerbub Waysf example temperature at which the carpet fails the test is at least b steb'reabbon Polymer may be mmersedm the as high as the temperature at which the carpet fails o the solutlon y be Sprayed upon fi Step 20 when sulfamide is used alone and is higher than when reabtlon Polymer or abbhed to the steb'reactlbn poly the above compound is used alone. These results indimor y means of b Tone cate that the use of sulfamide in conjunction with the The following examples serve to illustrate the process Previously described Compound gives a Synergistic d omp tion Of i116 invbntion- In the fOllOWing 25 feet which enhances the flame resistance of the carpet.

TABLE I WEIGHT PERCENT HIGHEST TEM- EXAMPLE COMPOSITION APPLIED TO PERATURE C CARPET l Sulfarnide 1O 2 2,4-dihydroxy benzoic acid 10.3 160 3 3 parts 2,4-dlhydroxy benzoic l 1.9

acid; I part sulfamide 4 Sodium malate 8.7 1 l5 5 l part sodium malate; 1 part 9.2 165 sulfamide 6 Sodium citrate 9.4 l 15 7 1 part sodium citrate; l 9.7 165 part sulfamide 8 Thiomalic acid I 1.5 9 1 part thiomalic acid; 1 part 8.2

sulfamide [0 Magnesium trithiocyanurate 7.5 120 l l 1 part magnesium trithiocyan- 7.2 160 urate; l part sulfamide l2 Lithium thiomalate 1 L0 120 l3 1 part lithium thiomalate; 10.4 190 1 part sulfamide l4 Tartaric acid 10.3 120 15 2 parts tartaric acid; 9.3

l part sulfamide amples the composition is applied to the step-reaction polymer, in the form of a carpet, by dipping the carpet into a solution of the composition and squeezing the clipped carpet to remove excess solution. The carpet is then dried and weighed so that the percentage of composition added to the carpet can be calculated. The flame resistance of the carpet is then measured using a modified US. Department of Commerce test DOC FF 70 wherein a 250 watt heat lamp is positioned 5 inches from the carpet surface and is controlled by a Variac. The lamp is turned on for 5 minutes at a preset voltage on the Variac in order to provide a more vigorous test. The higher the voltage applied to the heat lamp the greater the heat applied to the carpet prior to burning the carpet. The temperature of the carpet is measured with a thermocouple. The carpet is then burned by placing a 150 milligram methenamine pill in the center of the carpet. The pill is then ignited. The higher the temperature which can be applied to the carpet before the carpet fails to extinguish within 90 seconds after the In all cases parts and percentages are by weight unless otherwise indicated.

What is claimed is:

l. A composition for increasing flame resistance of a step-reaction polymer selected from the group consisting of polyesters, polyanhydrides, polyacetals, polyamides and polyurethanes comprising:

a. sulfamide; and

b. from about 40 to about 85 weight percent of a compound selected from the group consisting polyhydroxy-polycarboxy acids and their metal and ammonium salts, mercapto polycarboxylic acids and their metal and ammonium salts, polyhydroxy benzoic acids and their metal and ammonium salts, the lithium and sodium salts of monohydroxy polycarboxy acids, and the metal and ammonium salts of trithiocyanuric acid.

2. The composition of claim I wherein the compound is a lithium salt.

3. The composition of claim 1 wherein the compound is an alkali metal salt of trithiocyanuric acid.

4. The composition of claim 1 wherein the compound is gallic acid.

5. A step-reaction polymer selected from the group consisting of polyesters, polyanhydrides, polyacetals, polyamides and polyurethanes containing from about 1 to about weight percent of a composition comprismg:

a. sulfamide; and

b. from about 40 to about 85 weight percent of a compound selected from the group consisting polyhydroxy-polycarboxy acids and their metal and ammonium salts, mercapto polycarboxylic acids and their metal and ammonium salts, polyhydroxy benzoic acids and their metal and ammonium salts, the lithium and sodium salts of monohydroxy polycarboxy acids, and the metal and ammonium salts of trithiocyanuric acid.

6. A polymer in accordance with claim 5 wherein the polymer is nylon.

7. A method for increasing the flame resistance of a step-reaction polymer selected from the group consisting of polyesters, polyanhydrides, polyacetals, polyamides and polyurethanes comprising applying to the polymer from about 1 to about 15 weight percent of a composition comprising:

a. sulfamide; and b. from about 40 to about weight percent of a compound selected from the group consisting polyhydroxy-polycarboxy acids and their metal and ammonium salts, mercapto polycarboxylic acids and their metal and ammonium salts, polyhydroxy benzoic acids and their metal and ammonium salts, the lithium and sodium salts of monohydroxy polycarboxy acids, and the metal and ammonium salts of trithiocyanuric acid. 8. The method of claim 7 wherein the polymer is nylon.

9. The polymer of claim 5 wherein the polymer is polyurethane.

10. The method of claim 7 wherein the polymer is polyurethane. 

1. A composition for increasing flame resistance of a step-reaction polymer selected from the group consisting of polyesters, polyanhydrides, polyacetals, polyamides and polyurethanes comprising: a. sulfamide; and b. from about 40 to about 85 weight percent of a compound selected from the group consisting polyhydroxy-polycarboxy acids and their metal and ammonium salts, mercapto polycarboxylic acids and their metal and ammonium salts, polyhydroxy benzoic acids and their metal and ammonium salts, the lithium and sodium salts of monohydroxy polycarboxy acids, and the metal and ammonium salts of trithiocyanuric acid.
 2. The composition of claim 1 wherein the compound is a lithium salt.
 3. The composition of claim 1 wherein the compound is an alkali metal salt of trithiocyanuric acid.
 4. The composition of claim 1 wherein the compound is gallic acid.
 5. A STEP-REACTION POLYMER SELECTED FROM THE GROUP CONSISTING OF POLYESTERS, POLYANHYDRIDES, POLYACETALS, POLYAMIDES AND POLYURETHANES CONTAINING FROM ABOUT 1 TO ABOUT 15 WEIGHT PERCENT OF A COMPOSITION COMPRISING: A. SULFAMIDE; AND B. FROM ABOUT 40 TO ABOUT 85 WEIGHT PERCENT OF A COMPOUND SELECTED FROM THE GROUP CONSISTING POLYHYDROXYPOLYCARBOXY ACIDS AND THEIR METAL AMMONIUM SALTS, MERCAPTO POLYCARBOXYLIC ACIDS AND THEIR METAL AND AMMONIUM SALTS POLYHYDROXY BENZOIC ACIDS, AND THEIR METAL AND AMMONIUM SALTS, THE LITHIUM AND SODIUM SALTS OF MONOHYDROXY POLYCARBOXY ACIDS, AND THE METAL AND AMMONIUM SALTS OF TRITHIOCYANURIC ACID.
 6. A polymer in accordance with claim 5 wherein the polymer is nylon.
 7. A method for increasing the flame resistance of a step-reaction polymer selected from the group consisting of polyesters, polyanhydrides, polyacetals, polyamides and polyurethanes comprising applying to the polymer from about 1 to about 15 weight percent of a composition comprising: a. sulfamide; and b. from about 40 to about 85 weight percent of a compound selected from the group consisting polyhydroxy-polycarboxy acids and their metal and ammonium salts, mercapto polycarboxylic acids and their metal and ammonium salts, polyhydroxy benzoic acids and their metal and ammonium salts, the lithium and sodium salts of monohydroxy polycarboxy acids, and the metal and ammonium salts of trithiocyanuric acid.
 8. The method of claim 7 wherein the polymer is nylon.
 9. The polymer of claim 5 wherein the polymer is polyurethane.
 10. The method of claim 7 wherein the polymer is polyurethane. 